A filter is known from WO 2013 024105 A1 for the de-oiling of air originating from an air compressor or a vacuum pump. In this filter, a sealing connection between the filter elements and a U-shaped groove of a covering element of the filter is produced through the use of an adhesive or sealant. However, the use of adhesives for fixing the filter element is expensive and additionally problematic due to the partial uncertainty of the chemical and thermal stability.
A prototypical filter insert is known from WO 96 28238 A1. In this filter insert, a filter element wound on a support tube is connected by means of a flange connection or flanging with a mounting flange of the filter housing. A flange is understood here as a connection which is produced through right-angle bending of an edge of a round or oval metal sheet. The flange connection of WO 96 28238 A1 enables the omission of an adhesion of the filter element on the end face of the filter insert. For producing this flange connection, a flange ring is arranged in the end region of the air de-oiling element. This flange ring is a separate element which is not integrated in the end face covering element of the filter insert. The flange ring itself is not flanged, but rather serves as a counter support for a bead introduced in the mounting flange and the support tube.